Acid

Acids are a vital element in making shelf-stable pickles. Properly sealed jars of pickles can remain on the shelf for a long period of time because they have achieved an acceptable level of acidification, the pH of the contents (pickles and brine) has been stabilized, and all bacteria have been eradicated.

Acid in pickling takes two forms: vinegar and citric acid. Vinegar, an acetic acid, works on pickled vegetables to stabilize their pH levels. Different vinegars have different degrees of strength, or grain. Most vinegars commonly used in pickling have a grain strength of 5 or 6 percent. Avoid using vinegars with a grain strength lower than what the recipe requires, as this may result in pickles that don’t acidify properly. Citric acid takes the form of juice from citrus: lemon, lime, and orange. It brightens and embellishes the flavors of pickles and complements other ingredients, but it doesn’t usually provide the basis for acidification.